In peritoneal dialysis, dialysate is introduced into the peritoneal cavity through an indwelling catheter and, after a measured interval during which dialysis occurs within the patient with the peritoneal membrane serving as the diffusion membrane, is removed and discarded. Such a procedure has a number of advantages over conventional hemodialysis, such as the elimination of intravenous conditions, avoidance of the risks and complexities of external blood circulation, and the suitability of the procedure for patient self-treatment. In general, peritoneal dialysis is gaining recognition as a relatively simple, safe, and inexpensive alternative to hemodialysis. See K. M. Jones and P. Ivanovich, Peritoneal Dialysis-Treatment for End-Stage Diabetic Nephropathy, AmSect Proceedings, Vol. II, pp. 97-99 (1974).
The indwelling catheter commonly used in peritoneal dialysis is perforated at its distal end and is provided with at least one porous cuff of Dacron or other material suitable for tissue ingrowth and secured to the catheter tube at an intermediate location. The short proximal end portion of the catheter projects externally from the patient's abdominal wall and is adapted to be connected to conventional external dialysis equipment when a lavage procedure is to be undertaken. Such a catheter, although intended to be a permanent or at least a long-term implantation, may require surgical removal after only a few months of use should the lumen of the catheter become occluded by fibrin, or should the openings at the distal end become clogged or reduced to such an extent that the rate of flow of dialysate becomes unacceptably low. Since such problems develop well after tissue ingrowth into the cuff (or cuffs) of the catheter has occurred, replacement of the ingrown occluded catheter requires an operating room procedure. Not only is such surgery bothersome and costly; it is also unpleasant both physically and psychologically for the patient.
A main object of this invention therefore lies in providing a peritoneal catheter construction which substantially eliminates occlusion of the perforations and/or lumen of an indwelling catheter as a major problem in chronic peritoneal dialysis. More specifically, this invention is concerned with an improved indwelling catheter that may be replaced when necessary, to overcome problems of catheter occlusion, without the need for major surgery and without the physical and emotional disadvantages attending such surgery.
In brief, the peritoneal catheter of this invention is formed in two main sections which are normally connected together in fluid-tight relation but which may be separated should occlusion of the catheter take place. One of the sections, the retainer section, comprises a tubular sleeve equipped with an external porous fabric cuff for tissue ingrowth. The other section, the catheter tube section, normally extends through the bore of the retainer section and is releasably coupled thereto. The catheter tube section is provided with a rigid tubular plug sealingly bonded thereto, the plug having an external annular recess and being receivable in the bore of the sleeve so that an inward annular projection of the sleeve is received within the recess to produce a snug fluid-tight interfit between the parts.
In the disclosed embodiment, the sleeve is resilient and is reinforced in the zone of the inward annular projection by multiple windings extending about the sleeve and concealed by the ingrowth ring or cuff. The tension of the winding may be varied according to the resilience of the sleeve material, and the thickness of that material, to produce an effective seal and still provide a separable interconnection between the two sections of the catheter.
Other features, advantages, and objects of the invention will become apparent from the specification and drawings.